Head-Up Display (HUD) systems have become popular in a number of applications, including personal wearable devices. Generally, HUD systems present data to a user without requiring the user to look away from their usual viewpoints.
A near-eye display system creates a display in front of the user's field of vision and is an integral part of any HUD system. One of the limiting factors in designing a near-eye system for HUD systems is the human eye's accommodation. Accommodation is the process by which the human eye changes optical power to maintain a clear image or focus on an object as its distance varies. A normal human eye can typically comfortably focus on objects at a distance of 25 cm or greater, although studies have indicated that the minimum distance a normal human eye can focus (minimum amplitude of accommodation) can be as small as about 10 Dioptre, which is roughly around 10 cm.
Wearable HUD systems are generally intended for ease of portability and comfort of use. Compact systems that provide for the minimum amplitude of accommodation of a user's eye, are desirable.
Improvements in near-eye displays are desirable.